Monthly Archives: March 2017

We always advise our clients to order “LEGAL” paternity test with chain-of-custody if there is any kind of family dispute or even slightest possibility of court/legal proceedings. Result of legal paternity DNA test is defensible in court of law and you do not need to do it ever again.

Legal paternity DNA test can be effectively used for following situations:

Child Support

Child Custody

Immigration

Birth Certificate

Tax Forms

Will

Court Order

Adoption

Legal reasons

Your DNA samples will be tested at our accredited laboratory. Our laboratory technicians will carefully handle and prepare your DNA samples for processing. Every paternity test using cheek swabs is run two separate times in the lab and the results are triple-checked by our scientists. You never have to worry about a mix-up or wrong results. As soon as the results are verified, a legal document that is admissible in a court of law is mailed to you.

To undergo legal paternity test, you need to book an appointment, come with the child(ren), bring your original ID (identity documents) and one (1) passport size photo to the appointment. Our AABB trained and certified sample collection manager will help you fill-in all chain-of-custody documentation, will verify your identity and will collect your cheek swab samples.

Entire sampling process usually takes about 30-45 minutes in private consulting room at our facility in Accra. If you have any questions regarding the legal DNA test or chain-of-custody process, please call us on 0302-932267 or email us at info@dnacenterghana.com.

2000’s: SNP Arrays
In the early 2000’s, scientists were able to combine thousands of SNP (Single Nucleotide Polymorphism) loci into a single test. SNPs are letter changes in the DNA that can be used as genetic markers for a variety of applications. SNP arrays are not commonly used for relationship testing but are used for a number of other genetic tests including; predisposition to genetic disease, health and wellness, and ancestry. DDC uses a large 800,000 SNP custom array for the GPS Origins™ test. The array contains AIMs (Ancestry Informative Markers), Y-Chromosome markers, mitochondrial markers, ancient DNA markers, and other markers useful for establishing more distant biological relationships like 4th or 5th cousins.
2010’s: Next Generation Sequencing
NGS (Next Generation Sequencing) or Massively Parallel Sequencing is the newest technique available for genetic analysis. This procedure generates a DNA sequence that is the linear arrangement of letters (A, T, C, and G) that occur in a DNA sample. Because the technique allows one to simultaneously start the sequencing at thousands of locations in the DNA that overlap, massive amounts of data can be generated and put back together with appropriate bioinformatics programs. It would be like taking book and cutting out sections of sentences then reassembling the book using a computer program to recognize overlapping sentence fragments.

DDC currently uses NGS for its Non-Invasive Prenatal Paternity Test (NIPP) that can determine the biological father of a fetus as early as 8 weeks gestation using a blood sample from the mother. Before NIPP testing, a chorionic villus sample (cvs) or amniocentesis sample was required from the mother. Both of these procedures are invasive and have a small risk of damage to the fetus. The NIPP test is safe for the fetus and detects circulating cell free fetal DNA (cfDNA) in the mother’s plasma and sequences the DNA to interrogate several thousand SNPs.

1920s – Blood Typing

In the early 1900s, scientists identified 4 different blood types in humans – A, AB, B, and O – based on the presence of certain proteins called antigens in the blood. This blood typing system, called the ABO system, provided doctors with crucial information about their patients, allowing them to safely perform medical procedures, especially blood transfusions, by matching the blood types of patients and donors.

In the 1920s, scientists recognized that blood types were genetically inherited. A blood typing chart was developed to show the relationship between parents and their children.

Scientists realized that they could predict the blood type of a child based on his/her parents’ blood types. Conversely, if one of the parents’ blood types was unknown, the scientist could use the blood types of the child and the known parent to identify the missing parent’s blood type. In this way, scientists used blood typing to determine paternity or maternity of a child. However, because the information from blood typing is limited, it was difficult to definitively identify biological relationships.

For example, if a child had Type A blood and the child’s mother had Type AB blood, the child’s biological father could have any of the 4 blood types. This means that based on blood typing alone, no man could be excluded as the child’s father.

In the end, the power of exclusion (the power of a test to eliminate a certain percentage of the population from being biologically related to an individual) for blood testing is only 30%. Blood typing is not a useful technique for determining paternity.

1930s – Serological Testing

In the 1930s, scientists discovered other proteins in the blood that could be used for identifying humans. The Rh, Kell, and Duffy blood group systems, like the ABO system, were based on the presence of specific antigens in the blood. These antigens are also genetically inherited, proving useful in identifying possible biological relationships.

Through these serological tests, scientists could use the blood group systems of two parents to predict the possible blood group of their child. Scientists also applied serological testing to paternity cases, attempting to identify alleged fathers based on the blood groups of the child and mother. However, much like the use of the ABO system for paternity testing, serological tests are not conclusive in identifying biological parents. The power of exclusion for serological testing is only 40%, meaning this technique is not effective in identifying biological relationships.

1970s – HLA Testing

In the mid 1970s, scientists turned from blood typing to tissue typing. Scientists discovered the human leukocyte antigen (HLA), a protein prevalent in all of the body except the red blood cells. White blood cells in particular carry a high concentration of HLA. There are many different types of HLA, and these types vary between each person. Because of the high variability of HLA types between different people, HLA testing became a more powerful mode of paternity testing. The power of exclusion for HLA testing alone is 80% and coupled with blood typing and serological testing is close 90%.

Despite its more powerful ability to identify biological relationships, HLA testing is not an ideal technique. HLA testing requires a large blood sample that must be no older than a few days old. The collection process can be uncomfortable, making it dangerous for infants under the age of 6 months.

1980s – DNA Testing Using RFLP Technique

In the mid 1980s, a technique was developed called restriction fragment length polymorphism (RFLP, pronounced “rif-lip”). This technique became the first genetic test using DNA. Like HLA and blood proteins, DNA is genetically inherited from both parents. However, sections of DNA are highly variable and more unique than HLA and blood proteins, and it is found in every part of the body. These attributes make DNA ideal for identifying biological relationships.

RFLP allows scientists to cut out the unique sections of the DNA, which is extracted from blood samples. For paternity testing, these unique sections of the parents and child are compared. Half of the child’s DNA should match the mother’s DNA, and half should match thefather’s DNA if they are biologically related.

Sometimes during this procedure, the child’s DNA will not appear to match either parent’s DNA, possibly caused bygenetic mutations. When this occurs, scientists will perform statistical analysis to determine the possibilities of mutation and biological relationship between family members.

Because RFLP is applied to DNA testing, this procedure yields highly conclusive results, typically with a power of exclusion higher than 99.99%. However, this technique is not performed frequently today because, like HLA testing, RFLP requires a large blood sample and a longer turnaround time.

1990s – DNA Testing Using PCR Technology

Although developed in the 1980s, polymerase chain reaction (PCR) technique in DNA testing became the standard process for paternity testing in the 1990s.

PCR is a technique through which samples of DNA fragments are copied and replicated many times until billions of copies are made. Because of the power of PCR, very small samples of DNA from any part of the body can be used in a DNA test. Additionally, the process is quick.

By using PCR technology in DNA testing, paternity and other DNA tests can be performed much more easily and quickly. In a standard paternity test, DNA samples will be painlessly collected through buccal swabs from the mother, child, and alleged father. Then, the samples will be replicated through PCR and compared for similarities. Because half of the child’s DNA is inherited from the mother and the other half from the father, the child’s DNA should match portions of both biological parents.

Because DNA is being tested in this process, results yielded from a paternity test using PCR technology are often higher than 99.99%. This process has become the standard for biological identification, as it requires only a small sample from any person (even in prenatal cases), is highly conclusive, and provides results very quickly.